The Android ProgressBar is a useful UI component that most developers will quickly find need of. Displaying progress, even an indeterminate “loading” indicator, provides crucial feedback to a user, eliminating frustration and confusion while your app is churning away in the background.

Today I’ll demonstrate using an indeterminate ProgressBar within a ListView while loading web content. I’ll be modifying the TweetView project from my previous post.

Last week I demonstrated designing and implementing customized layouts for Android ListView items, including some simple example code. Today i’ll expand on that code to make something a little closer to an actual app: a Twitter feed reader for Android. I’ll use this exercise to illustrate some new tools and concepts in the process such as working with JSON data and the Android BitmapFactory.